/ Thesaurus / T Synonyms of treasonist Find synonyms for: Noun1. traitor, treasonist, criminal, felon, crook, outlaw, malefactorusage: someone who betrays his country by committing treasonWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: ravenous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language